#prefer-export-from

#Configuration

import { defineConfig, unicornPlugin } from '@rslint/core';

export default defineConfig([
  unicornPlugin.configs.recommended,
  {
    rules: {
      'unicorn/prefer-export-from': 'error',
    },
  },
]);

#Rule details

Prefer export…from when forwarding bindings from another module. The rule checks named, default and namespace imports, including single export const aliases whose local name is unused. An attached JSDoc comment keeps such an alias in place.

Example of incorrect code for this rule.

import { parse } from './parser.js';
export { parse };

Example of correct code for this rule.

export { parse } from './parser.js';

#Fixes and suggestions

Fixes keep imports with other references and value imports that are re-exported only as types. Comments inside the declarations limit the rule to a diagnostic.

An export…from declaration exposes a live binding. When a fix replaces export default value or export const alias = value, updates to the source binding become visible to consumers of the re-export.

#Options

#checkUsedVariables

Type boolean. Default true.

Set this option to false to skip an entire import declaration when any of its bindings is used outside a re-export. When the declaration contains both re-exported and unused bindings, the rule offers a suggestion for the re-exports.

{
  "unicorn/prefer-export-from": ["error", { "checkUsedVariables": false }]
}

#Differences from upstream

• Fixes preserve dependency evaluation order. If a file imports ./setup.js before ./consumer.js, the direct re-export of ./setup.js stays before ./consumer.js. Re-exports with different with attributes stay separate.
• Re-exporting ns from import main, * as ns from 'lib' keeps the default import valid. Imports used as JSX factories also stay in place, including custom factories and imports used after a local binding shadows the factory elsewhere in the file.
• With verbatimModuleSyntax enabled in the linted project, import {type T} stays in place when it is the only binding in the declaration. The import can still load the dependency at runtime.
• Re-exports inside declare module and re-exports of import defer bindings receive diagnostics only. Direct eval() also blocks edits that would remove a local binding it could read.
• For files using legacy assert { … } import assertions, switch to with { … } import attributes before applying the rule.

#Original documentation

• eslint-plugin-unicorn: prefer-export-from
• Source code